The present invention relates to surf pools and particularly to valves used in surf pools for rapidly releasing relatively large quantities of water to create surf.
Pools of water in which waves forming surf may be created are known. Various methods of creating surf have been devised yielding differing results. For example, in U.S Pat. No. 2,056,855 to Herz apparatus for making surf is disclosed. There, a water chamber is disposed at a deep end of a pool and is in communication below the water surface with the water in the pool. Air is alternately and repetitively extracted from, and blown into, the chamber creating waves in the pool as water passes through the opening between the chamber and pool, first in one direction, then in the other. U.S. Pat. No. 3,473,334 to Dexter discloses another apparatus for creating waves and surf in a pool. The patent to Dexter shows a reservoir at the deep end of a pool that may be in communication below the water surface with the water in the pool. A large gate may be rapidly opened or closed to create or cut off, respectively, the communication between the reservoir and the pool. When the gate is closed, water is pumped into the reservoir to a level above that of the water in the pool. Upon the opening of the gate, water flows downward in the reservoir and upward into the pool creating a wave. The gate is then closed and the process repeated.
Other types of equipment are used to make different types of waves in swimming pools. For example, see U.S. Pat. Nos. 3,629,877 to Schuster et al. and 4,276,661 to Baker. These other types of wave making equipment generally do not use valves as Dexter does.
Although the Dexter disclosure permits construction of apparatus producing waves of sufficient height for surfing, the valve he discloses, a gate that is rapidly raised and lowered by hydraulic means, was not successful. Various other constructions of valves that will quickly release large quantities of water to produce a surfing wave have been attempted. In one such construction a gate like Dexter's is fixed to a generally horizontal arm that is pivoted on the end opposite the gate. A hydraulic cylinder is attached to the arm and hung from the ceiling of the reservoir. To open the gate, the arm is lifted by the hydraulic cylinder. The large forces needed to rapidly operate this valve result in damage to the reservoir ceiling. In another similar construction, the hydraulic actuator is connected to the arm and mounted on the floor of the reservoir. While this arrangement does operate the gate satisfactorily, it creates other problems. The hydraulic cylinder is always submerged and therefore subjected to the chlorinated water of the pool. The fluid in the hydraulic cylinder can leak, contaminating the pool water. Any maintenance work to be performed on the hydraulic actuator must be performed underwater or the pool must be drained. Since the typical surf pool contains several million gallons of water, draining and refilling the pool is exceedingly expensive and time consuming. Both of these valve constructions require the lifting of the entire weight of the valve by the cylinder. Therefore only a hydraulic cylinder is sufficiently powerful to open these valves.